LS7213

UL ® LSI/CSI LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 D3 D2 A B V SS (-V) LS7213 (631) 271-0400 FAX (631) 271-0405 August 2001 PIN ASSIGNMENT TOP VIEW 1 LSI 2 3 14 13 12 A3800 PROGRAMMABLE DIGITAL DELAY TIMER FEATURES: Eight timing ranges Four modes RC controlled on-chip oscillator Power-On-Reset (POR) Reset input for delay abort Complementary outputs Delay-in-Progress Indicator output LS7213 (DIP), LS7213-S (SOIC) - See Figure 1 APPLICATIONS Time delay relays for HVAC equipment and industrial controls. DESCRIPTION The LS7213 is a monolithic CMOS integrated circuit for generating programmable time-delays. The delay is initiated by a logic transition at the Trigger input and the completion of the delay is marked by a change of status at the Out1 and the Out2 outputs. Three inputs, D1, D2 and D3 select 1-of-8 scale factors, s. The delay, td is related to s by the expression, td = s/f rc, where f rc is the frequency at the RC input produced by an internal oscillator. An external resistor-capacitor pair connected to the RC pin controls the oscillator frequency. There are four modes of operation selected by inputs A and B. The operating modes are: On-Delay (OND), Off-Delay (OFD), Dual-Delay (DLD) and OneShot(OST). These modes are described below: On-Delay (OND) Mode A positive transition at the Trigger input starts the on-delay timer. At the end of the delay Out1 switches low and Out2 switches high. A negative transition at the Trig...